1. Field of the Invention
The present invention relates to a hybrid vehicle propulsion apparatus comprising an internal combustion engine having an output shaft and a motor generator coupled directly to the output shaft.
2. Description of the Related Art
There has been proposed a hybrid vehicle having an internal combustion engine for generating propulsive forces by combusting gasoline and a motor generator which can be operated as an electric generator for regenerating electric energy and an electric motor for generating propulsive forces with electric energy to assist propulsive forces produced by the internal combustion engine. The propulsive forces produced by the internal combustion engine and the electric motor are combined as required to propel the vehicle. For details, reference should be made to Japanese laid-open patent publication No. 9-156388.
A flywheel is usually connected to the crankshaft of the internal combustion engine for smoothing and stabilizing the rotation of the internal combustion engine. With the motor generator coupled to the crankshaft, since the rotation of a rotor, which is relatively heavy, of the motor generator tends to affect the rotation of the crankshaft, it is preferable to position the motor generator as closely to the crankshaft as possible. Positioning the motor generator as closely to the crankshaft as possible is effective to increase the rigidity of the motor generator.
However, the motor generator that is located closely to the internal combustion engine poses a problem in that leakage currents and leakage fluxes from coils of the motor generator influence the internal combustion engine which is made of metal, adversely affecting the rotation of the crankshaft.
On a manual-transmission hybrid vehicle, it is necessary to position a clutch mechanism between the internal combustion engine and the transmission or between the motor generator and the transmission. If the clutch mechanism is disposed closely to the motor generator, then metal particles produced by the clutch mechanism may be liable to enter the motor generator, adversely affect propulsive forces generated by the motor generator. Specifically, if metal particles contained in an abrasive powder produced when the friction plates of the clutch mechanism are engaged and disengaged are attracted to the magnets of the motor generator, then the metal particles are magnetized and generates magnetic fields, which then adversely affect the electromotive forces or propulsive forces that are generated. If the metal particles enter between the rotor and stator of the motor generator, then they are apt to increase the resistance to the rotation of the rotor, thereby adversely affecting the propulsive forces that are generated.
It is a general object of the present invention to provide a hybrid vehicle propulsion apparatus which has a motor generator disposed closely to an internal combustion engine for allowing a crankshaft to rotate in good conditions and preventing the internal combustion engine from being adversely affected by leakage currents and leakage fluxes from coils of the motor generator.
A major object of the present invention is to provide a hybrid vehicle propulsion apparatus which is effective to prevent an internal combustion engine from being adversely affected by leakage currents and leakage fluxes from coils of a motor generator, and which is relatively compact.
Another object of the present invention is to provide a hybrid vehicle propulsion apparatus which is effective to prevent leakage currents and leakage fluxes from coils of a motor generator from adversely affecting a flywheel, a clutch mechanism, a transmission, etc., and which is relatively compact.
Still another object of the present invention is to provide a hybrid vehicle propulsion apparatus which is free of adverse effects due to leakage currents and leakage fluxes from coils of a motor generator, and which is of relatively high rigidity.
Yet still another object of the present invention is to provide a hybrid vehicle propulsion apparatus which prevents metal particles contained in an abrasive powder produced by a clutch mechanism from entering a motor generator for thereby maintaining a desired level of performance of a motor generator.
The above and other objects, features, and advantages of the present invention will become more apparent from the following description when taken in conjunction with the accompanying drawings in which preferred embodiments of the present invention are shown by way of illustrative example.